AMD-751 Datasheet, PDF (10/14 Pages) Advanced Micro Devices – AMD-751-TM System Controller Revision Guide

Preliminary Information
AMD-751™ System Controller Revision Guide
22564B-1—February 2000
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Burst Writes to Non-Existent AGP Memory Hang System
Products Affected. C3 and C5
Description. Running in DOS under Windows, MechWarrior2 creates burst writes to non-existent AGP
memory that intentionally cause master abort cycles from the S3 Savage4 graphics card to the system
controller. The AMD-751 system controller does not handle master abort cycles in the quantity
generated by the S3 Savage4 graphics card. This behavior to the system controller is caused by the
software/driver when write combining is enabled and is not considered appropriate nor indicative of
any common software technique. Write combining is enabled when the AMD AGP miniport driver is
installed.
Potential Effect on System. System hangs.
Suggested Workarounds.
I. Run the game differently:
1. Install and run the game directly under DOS, creating a BOOT floppy when asked.
2. Obtain the Windows version of the program on CD.
3. Upgrade to the newer MechWarrior3 product.
II. Change the BIOS
1. APC write chaining, device 0, function 0, register 84h, bit 17 must be left at 0.
Resolution Status. No planned fix.
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